plant growth regulator

Plant growth regulators can affect many physiological and biochemical processes of crops by regulating the level of plant endogenous hormones. At present, they have become an important part of the new agricultural technology of high yield, stable yield and efficiency in crop production in China, and play a pivotal role in maize production.

The application of plant growth regulators in maize can not only promote germination and cultivate strong seedlings, but also promote the filling of maize seed, and improve the quality of maize while increasing the yield. Some growth regulators have the function of increasing yield and improving quality, and the application time is generally in the late stage of maize growth.

The editor has sorted out some growth regulators that can be applied in the growth period of corn and the effects they can bring for your reference

・ I. Prevent maize from lodging and control its prosperity

ethephon 

According to the test report, the application of ethephon in maize can promote the root development, play a role in dwarfing and strengthening the stem, enhance the field ventilation and light, and promote early maturity. Spraying 800-1000mg/L solution after jointing and before heading can play a role in dwarfing and increasing yield.

Attention should be paid to the use: strictly control the use concentration. If the use concentration is too high, it will cause excessive inhibition of stem growth and affect the yield; Grasp the use period to prevent early or late application; The spray shall be even to prevent uneven application from causing irregular growth.

Chlormequat

Dilute 50% aqueous solution by 80-100 times, immerse seeds by submerging seeds, and sow after drying in the shade. The plant is short and strong, the root system is developed, the ear position is low, there is no bald tip, the ear is large and the grain is full, and the yield is significant. Using 0.2-0.3% liquid medicine at seedling stage and spraying 50kg per mu can play the role of crouching seedlings, resist saline-alkali and drought, and increase yield by about 20%. Using 1000-3000ppm/L liquid medicine, spraying 30-50kg/mu liquid medicine on the leaves 3-5 days before jointing, the internode shortened, the ear position decreased, the lodging resistance, the leaves were short and wide, the photosynthesis increased, the bald tip decreased, the double ear rate increased, the 1000-grain weight increased, and the yield increased.

● Improper variety selection, unreasonable planting density, unscientific fertilizer and water management, and late chemical control may cause maize lodging.

(II) Promote early maturing and yield increase of corn

gibberellin

After the female flower of corn is fertilized, when the filaments begin to scorch, spraying 50kg of 40-100mg/L gibberellin solution per mu or pouring it into the bracts (about 1mL plants) can reduce the bald tip, increase the number of grains, promote filling, and increase the weight of 1000 grains. In production, 4% gibberellin emulsifiable concentrates can be diluted 400-1000 times to obtain 40-100mg/L gibberellin solution, which can be sprayed on leaves.

Attention should be paid to the use of the agent; Strictly control the use concentration; It should be applied in sunny days, and should be supplemented in case of rain within 6 hours after the application.

III. Promote rooting and germination

Amine fresh fat

Soak seeds at 15ppm for 6-16h, spray once at seedling stage, young spike differentiation stage and heading stage respectively. Improve the germination rate, plant robust, leaf color thick green, grain number full, bald and pointed degree shortened, grain ear number and 1000-grain weight increased, lodging resistance, prevention and control of red leaf disease, early maturity, high yield.

● The application time of different growth regulators is different, the corresponding corn growth period is different, and the technical requirements for use are high. Please clarify before application.

Correct understanding of plant growth regulators

In the process of maize planting, the application of plant growth regulators to regulate and control the growth and development of maize and reduce the plant height and ear height can increase the density of maize per unit area, increase the number of ears, early maturity, stable yield and yield, and give full play to the population advantages of maize. Due to lack of understanding, farmers have many improper or mistakes in the use of plant growth regulators.

Maize growth regulators can be divided into single agent and mixture. The use of single agent has certain side effects. The mixture can achieve the combination of quick and long-term effects, and is generally used more. In maize production, growth promoters, growth retardants, growth inhibitors and ethephons are mainly used, with most of them being retardants.

Significant effect on improving yield, quality and economic benefits

Using plant growth regulators to treat seeds and spraying in the middle and late stages of growth can significantly improve yield, quality and economic benefits. Soaking or dressing corn seeds with plant growth regulators is conducive to breaking the dormancy of seeds, promoting the rooting and germination of seeds, ensuring the germination rate, and the vigorous growth of corn seedlings, which can extend the growth time of corn in the field and lay the foundation for high and stable yield.

Regulate the growth period of maize and enhance the ability of resistance to adversity and lodging

Maize has the characteristics of rapid growth. Applying plant growth regulators can effectively control the rapid growth of maize, inhibit the apical dominance, and make maize plant height shorter.

1. Nutrition supply and growth reversal of maize

When the rapid growth is inhibited, the nutrient supply and growth trend of maize will reverse, and the plant height traits of maize will turn to the development of plant height shortening, stem thickening, root strengthening, and leaf thickening. The lodging resistance of maize plants will be significantly enhanced, with low empty stem rate, small bald tip, and stronger disease resistance.

2. Changes of plant ear position characters

The rapid growth of maize was inhibited, and the plant ear position characters were changed, which improved the maize pollination rate, reduced the bald tip of maize, reduced the empty plant rate, and promoted the reproductive growth, making the maize ear thick, increased the number of grains per ear, and increased the grain weight per ear. In the harvest period, the number of grains, 100-grain weight, yield and other aspects of corn have been improved to a certain extent. According to statistics, the production increase can reach 8% - 12%.

3. Improve photosynthetic efficiency

The application of growth regulators in maize can increase the leaf area of maize, shorten the functional leaf nodes, improve the photosynthetic efficiency, accelerate the synthesis of photosynthetic products and flow to the ear; It makes the ear rachis longer and thinner, the grains thicker, the 100-grain weight increased, and can mature 5 to 7 days earlier, with timely and late harvest, which is of great significance for yield increase.

4. Reduce field shading

After applying growth regulator, the plant type of maize is compact and the field shade is reduced. After the application of growth regulators, the upper leaves of maize ear were generally lifted, the plant converged, the leaf angle became smaller, and the ventilation and light transmission conditions were improved; The leaves thicken, the color darkens, the chlorophyll content increases, the leaf function strengthens, and the photosynthesis enhances; Improve the resistance of maize, delay the senescence of maize plant, promote the growth and development of maize, and achieve the purpose of increasing yield.

5. Promote the development of maize root system

The application of growth regulators can effectively inhibit the vegetative growth of the aboveground parts of maize plants and promote the growth of maize roots. The growth of maize root system has been significantly improved, the root amount of aerial root and underground secondary root has doubled, and the root absorption area has increased by 2-3 times, ensuring the supply of nutrients, making maize grow healthily, the stem is tough, and the drought resistance and lodging resistance have been improved. In addition, the productivity of maize per plant has been improved, and the yield increase effect is obvious.

6. Promote fruit ripening

Proper use of growth regulators can delay the senescence of maize roots and leaves in the later stage, increase the growth time of maize, and promote fruit ripening.

7. Reduce the impact of adverse weather conditions

After the application of growth regulator, the booting time of maize will increase, and the adverse effects of low light, low temperature and heavy rain on maize growth will be reduced.

8. It can increase the planting density of corn

If growth regulators are used, the planting density of corn can be appropriately increased. The use of regulators can significantly increase the stem strength and reduce the probability of lodging the corn stem, so the density can be appropriately increased during planting.